Disclosure of Invention
The embodiment of the invention provides a packer, and aims to solve the problems of short service life and low unsealing success rate of the packer in the related art. The technical scheme is as follows:
a packer is provided, the packer comprising: the rubber tube comprises a mandrel, a first sliding sleeve, a second sliding sleeve, a rubber tube, a first pin and a second pin;
the mandrel is provided with a cavity inside, the mandrel is coaxially inserted into the first sliding sleeve and the second sliding sleeve, the outer diameter of the first end of the mandrel is smaller than that of the second end of the mandrel, an elastic convex ring is arranged on the outer wall of the first end of the mandrel, and a first pressure transmission hole penetrating through the inner wall and the outer wall is formed in the side wall of the first end of the mandrel;
the outer wall of the second end of the mandrel is provided with a rubber cylinder groove and a second sliding sleeve groove which are separated from each other, the rubber cylinder groove is communicated with the cavity inside the mandrel through a second pressure transmission hole, the rubber cylinder is positioned in the rubber cylinder groove, and two ends of the rubber cylinder are abutted against two ends of the rubber cylinder groove; the second sliding sleeve groove is communicated with the cavity in the mandrel through a third pressure transfer hole;
the first sliding sleeve is connected with the mandrel through the first pin, one end of the first sliding sleeve is provided with a clamping ring which extends radially inwards to be in contact with the outer wall of the first end of the mandrel, the clamping ring is positioned between the elastic convex ring and the first pressure transmission hole, and the inner wall of the clamping ring is provided with a groove matched with the elastic convex ring in size; the rubber sleeve groove is positioned between two axial ends of the first sliding sleeve;
the second sliding sleeve is connected with the mandrel through the second pin; a liquid discharge hole penetrating through the inner wall and the outer wall is formed in the side wall of the second sliding sleeve and is positioned between the two axial ends of the second sliding sleeve groove; and a separating ring which radially and inwardly extends to be in contact with the outer wall of the second end of the mandrel is arranged on the inner wall of the second sliding sleeve, and the separating ring is axially positioned between the liquid discharge hole and the third pressure transmission hole.
Optionally, the elastic male ring comprises an elastic member and a locking male ring;
an annular groove is formed in the outer wall of the first end of the mandrel, the elastic component is fixed in the annular groove, and the elastic component is in a release state during assembly; the locking convex ring is connected with the elastic component;
the end face of one end, close to the clamping ring, of the locking convex ring is an inclined face, and the distance between the inclined face and the end face of the other end of the locking convex ring is gradually increased along the radial inward direction; the end face of one end, close to the locking convex ring, of the clamping ring is matched with the inclined face.
Optionally, a check valve with a liquid inlet in a radially inward direction is arranged in the liquid discharge hole.
Optionally, check valves with liquid inlets facing radially inward are arranged in the first pressure transfer hole, the second pressure transfer hole and the third pressure transfer hole;
the opening pressures of the check valves in the first pressure transmission hole, the second pressure transmission hole and the third pressure transmission hole are increased in sequence.
Optionally, the mandrel further comprises: a first seal groove; the first sealing groove is located on the outer wall of the mandrel, which is in contact with the first sliding sleeve, and a sealing ring is arranged in the first sealing groove.
Optionally, the mandrel further comprises: a second seal groove; the second sealing groove is located on the outer wall of the mandrel, which is in contact with the second sliding sleeve, and is located between the rubber sleeve groove and the second sliding sleeve groove, and a sealing ring is arranged in the second sealing groove.
Optionally, the second runner comprises: a third seal groove; the third seal groove is located on the inner wall of the separating ring in contact with the second end of the mandrel, and a seal ring is arranged in the third seal groove.
Optionally, the mandrel further comprises: a fourth seal groove; the fourth sealing groove is located on the outer wall of the mandrel, which is in contact with the second sliding sleeve, and the fourth sealing groove is axially located on one side, away from the first sliding sleeve, of the second sliding sleeve groove, and a sealing ring is arranged in the fourth sealing groove.
The technical scheme provided by the embodiment of the invention has the beneficial effects that at least:
according to the technical scheme provided by the embodiment of the invention, the rubber sleeve is protected by the first sliding sleeve covering the rubber sleeve in the well entering process of the device, after the device reaches an operation position, the first sliding sleeve is controlled to slide along the axial direction in a pressurization mode in an oil pipe so as to expose the rubber sleeve, the rubber sleeve is expanded by continuously pressurizing, and then the packer is successfully set; when the packer is unsealed, the second sliding sleeve is continuously pressurized and controlled to slide axially to enable the rubber sleeve to be fully recovered, and the second sliding sleeve covers the rubber sleeve again to protect the rubber sleeve. The device simple structure, convenient to use, the protection mode of overlay type has not only reduced the wearing and tearing of packing element, has still avoided the fluid erosion to the packing element in the pit shaft, therefore has prolonged the life of packer, has increased the success rate of packer setting, deblocking to make the packer can follow the drilling and go into the well, enlarged the operation scope of packer.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
The embodiment of the invention provides a packer, and referring to fig. 1, the packer comprises a mandrel 1, a first sliding sleeve 2, a second sliding sleeve 3, a rubber sleeve 4, a first pin 5 and a second pin 6;
the inner part of the mandrel 1 is a cavity, the mandrel 1 is coaxially inserted into the first sliding sleeve 2 and the second sliding sleeve 3, the outer diameter of the first end of the mandrel 1 is smaller than that of the second end of the mandrel 1, an elastic convex ring 11 is arranged on the outer wall of the first end of the mandrel 1, and a first pressure transmission hole 12 penetrating through the inner wall and the outer wall is formed in the side wall of the first end of the mandrel 1;
the outer wall of the second end of the mandrel 1 is provided with a rubber cylinder groove 13 and a second sliding sleeve groove 14 which are separated from each other, the rubber cylinder groove 13 is communicated with the cavity inside the mandrel 1 through a second pressure transmission hole 15, the rubber cylinder 4 is positioned in the rubber cylinder groove 13, and two ends of the rubber cylinder 4 are abutted against two ends of the rubber cylinder groove 13; the second sliding sleeve groove 14 is communicated with a cavity inside the mandrel 1 through a third pressure transmission hole 16;
the first sliding sleeve 2 is connected with the mandrel 1 through a first pin 5, a first end of the first sliding sleeve 2 is provided with a snap ring 21 which extends radially inwards to be in contact with the outer wall of the first end of the mandrel 1, and the snap ring 21 is positioned between the elastic convex ring 11 and the first pressure transmission hole 12; the rubber barrel groove 13 is positioned between the two axial ends of the first sliding sleeve 2;
the second sliding sleeve 3 is connected with the mandrel 1 through a second pin 6; the side wall of the second sliding sleeve 3 is provided with a liquid discharge hole 31 penetrating through the inner wall and the outer wall, and the liquid discharge hole 31 is positioned between the two axial ends of the second sliding sleeve groove 14; the inner wall of the second sliding sleeve 3 is provided with a separating ring 21 which extends radially inwards to be contacted with the outer wall of the second end of the mandrel 1, and the separating ring 21 is axially positioned between the liquid discharge hole 31 and the third pressure transmission hole 16.
Next, a description will be given of a use process of the packer provided in the present embodiment:
when the device is used, the device is connected with a drill pipe or an oil pipe through threads at two ends of the mandrel 1 and is lowered into a well bore, and as shown in figure 1, the device is in a closed state: the first sliding sleeve 2 is fixedly connected with the mandrel 1 through a first pin 5, the second sliding sleeve 3 is fixedly connected with the mandrel 1 through a second pin 6, and the first sliding sleeve 2 covers the rubber barrel 4 to protect the rubber barrel 4. Of course, in addition to the threaded connection, the present embodiment may also adopt other connection methods such as welding connection, etc. to achieve connection between the device and the drill rod or the oil pipe.
When the device needs to be opened, the pressure is slowly increased through a drill rod or an oil pipe, high-pressure liquid enters a cavity formed by the inner wall of the first sliding sleeve 2, the end face of one end, close to the sliding sleeve groove 13, of the clamping ring 21, the outer wall of the first end of the mandrel 1 and the end face of the second end of the mandrel 1 through the first pressure transmission hole 12, and the stress of each face forming the cavity is gradually increased due to continuous entering of the high-pressure liquid. Wherein, the atress direction of the inner wall of first sliding sleeve 2 and the outer wall of the first end of dabber 1 is radial, because first sliding sleeve 2 and dabber 1 are the rigid structure that inside is the cavity, therefore first sliding sleeve 2 and dabber 1 only produce the small deformation that the deformation volume can be ignored in this direction.
The stress directions of the end surface of one end of the snap ring 21 close to the sliding sleeve groove 13 and the end surface of the second end of the mandrel 1 are both axial, wherein the two ends of the mandrel 1 are fixedly connected with a drill rod or an oil pipe, so that the mandrel 1 does not displace in the axial direction, and the snap ring 21 generates a displacement trend towards the direction close to the elastic convex ring 11 under the action of high-pressure liquid; when the axial force of the snap ring 21 is greater than the shearing force of the first pin 5, the first pin 5 is sheared, the volume of the high-pressure liquid entering the cavity is gradually increased, and the snap ring 21 and the first sliding sleeve 2 are further pushed to displace towards the direction close to the elastic convex ring 11.
In the displacement process, as shown in fig. 2, when the end surface of the snap ring 21 near one end of the elastic convex ring 11 moves to contact with the elastic convex ring 11, the elastic convex ring 11 is compressed, and the snap ring 21 and the first sliding sleeve 2 continue to displace along the direction under the action of the high-pressure liquid; when the groove 211 on the inner wall of the snap ring 21 is displaced to face the elastic convex ring 11, the elastic convex ring 11 is released from the compressed state, and the elastic convex ring 11 enters the groove 211 under the elastic action to lock the snap ring 21 and the first sliding sleeve 2.
After the snap ring 21 and the first sliding sleeve 2 are locked, the rubber sleeve 4 is completely exposed, and is continuously slowly pressurized through a drill rod or an oil pipe, then high-pressure liquid enters the rubber sleeve groove 13 through the second pressure transmission hole 15, under the radial acting force of the high-pressure liquid, as shown in fig. 2, the rubber sleeve 4 in the rubber sleeve groove 13 bulges, the inner diameter and the outer diameter of the rubber sleeve 4 are gradually increased until the outer wall of the rubber sleeve 4 and the inner wall of a shaft are mutually extruded, then the rubber sleeve 4 seals an annular space between the oil pipe and the inner wall of the shaft, and the device completes setting.
When the unsealing device needs to be unsealed, as shown in fig. 3, the drill pipe or the oil pipe continues to slowly pressurize, then the high-pressure liquid enters a cavity formed by the inner wall of the second sliding sleeve 3, the end surface of one end of the separating ring 32 far away from the sliding sleeve groove 13, the outer wall of the second end of the mandrel 1 and the end surface of one end of the second sliding sleeve groove 14 far away from the sliding sleeve groove 13 through the third pressure transfer hole 16, and the continuous entering of the high-pressure liquid causes the stress of each surface forming the cavity to be gradually increased; when the axial force of the separating ring 32 is greater than the shearing force of the second pin 6, the second pin 6 is sheared, the volume of the high-pressure liquid entering the cavity is gradually increased, and the separating ring 32 and the second sliding sleeve 3 are pushed to displace towards the direction close to the rubber barrel groove 13.
In the displacement process, the swelled rubber tube 4 is pressed back into the sliding sleeve groove 13 under the action of the second sliding sleeve 3, and the rubber tube 4 is gradually covered by the second sliding sleeve 3 along with the increase of the displacement distance of the second sliding sleeve 3. The reason why the second sliding sleeve 3 is adopted to press the rubber sleeve 4 back to the sliding sleeve groove 13 is that the rubber sleeve 4 can generate unrecoverable plastic deformation in the bulging process, and if a pressure relief mode is adopted and the rubber sleeve 4 is automatically recovered, the rubber sleeve 4 cannot be completely recovered, so that the second sliding sleeve 3 is adopted to press the rubber sleeve 4 back to the sliding sleeve groove 13 in the embodiment, and the sufficient recovery of the rubber sleeve 4 is ensured.
In addition, in the displacement process, the liquid discharge hole 31 penetrating through the inner wall and the outer wall on the side wall of the second sliding sleeve 3 is always communicated with a cavity formed by the inner wall of the second sliding sleeve 3, the outer wall of the second end of the mandrel 1, the end surface of one end of the second sliding sleeve groove 14 close to the rubber sleeve groove 13 and the end surface of one end of the separating ring 32 close to the rubber sleeve groove 13, so that liquid in the cavity can be discharged to the outside of the device through the liquid discharge hole 31.
The liquid in the cavity may be a high-pressure liquid (e.g., high-pressure oil) used when the liquid is pressurized through a drill pipe or an oil pipe, or may be a liquid medium used in drilling operations, well washing operations, and other operations. The liquid in the cavity is discharged through the liquid discharge hole 31, so that the situation that the second sliding sleeve 3 cannot be displaced towards the direction close to the rubber sleeve groove 13 due to the fact that the liquid in the cavity is not compressible is avoided.
In the embodiment of the present invention, by adjusting the tensile strength of the rubber sleeve 4 and the shear strengths of the first pin 5 and the second pin 6, the shear pressure required by the first pin 5 is smaller than the pressure required by the rubber sleeve 4 to swell, and the shear pressure required by the rubber sleeve 4 to swell is smaller than the shear pressure required by the second pin 6, so that the first pin 5 is firstly sheared, the rubber sleeve 4 is secondly swelled, and the second pin 6 is finally sheared during the pressurization process through the drill pipe or the oil pipe, thereby opening, setting and unsealing the device during the above-mentioned use process can be achieved.
In an alternative embodiment, as shown in fig. 4, the elastic collar 11 includes an elastic member and a locking collar; the outer wall of the first end of the mandrel 1 is provided with an annular groove, the elastic component is fixed in the annular groove, and the elastic component is in a release state during assembly; the locking convex ring is connected with the elastic component;
the end surface of one end of the locking convex ring close to the snap ring 21 is an inclined surface, and the distance between the inclined surface and the end surface of the other end of the locking convex ring is gradually increased along the radial inward direction; the end surface of the snap ring 21 near one end of the locking convex ring is matched with the inclined surface.
In this embodiment, when the snap ring 21 and the first sliding sleeve 2 move to the direction close to the locking convex ring until they contact with the locking convex ring, the end surfaces of the snap ring 21 and the locking convex ring close to each other have mutually matched inclined surfaces, so that the locking convex ring is pushed to move in the radial inward direction, the resistance of the locking convex ring in the process of entering the groove 211 is reduced, and the working efficiency of the device is improved.
In addition, the liquid discharge hole 31 is internally provided with a one-way valve with a liquid inlet in a radial inward direction, and liquid can only flow from the liquid inlet of the one-way valve to the liquid outlet of the one-way valve, so that the liquid in a cavity communicated with the liquid discharge hole 31 in the device can flow out of the device through the one-way valve, and the liquid outside the device cannot enter the device through the one-way valve, thereby ensuring the sealing property of the device.
Optionally, the first pressure transmission hole 12, the second pressure transmission hole 15 and the third pressure transmission hole 16 are all provided with check valves with liquid inlets facing radially inwards, that is, the liquid in the check valves all flows from the cavity inside the mandrel 1 to the outside of the mandrel 1. When the liquid pressure of the liquid inlet of the one-way valve is smaller than the pressure in the nitrogen cavity, the one-way valve is in a closed state, and liquid cannot pass through the one-way valve; when the liquid pressure of the liquid inlet of the one-way valve is larger than the pressure in the nitrogen cavity, the one-way valve is opened, and then liquid can flow from the liquid inlet of the one-way valve to the liquid outlet.
It should be noted that the pressure in the nitrogen gas chamber is adjustable, in this embodiment, the opening pressures of the check valves in the first pressure transfer hole 12, the second pressure transfer hole 15, and the third pressure transfer hole 16 are sequentially increased, that is, the pressures of the nitrogen gas chambers in the check valves in the first pressure transfer hole 12, the second pressure transfer hole 15, and the third pressure transfer hole 16 are sequentially increased, so that in the process of pressurizing through the oil pipe, the check valves in the first pressure transfer hole 12, the second pressure transfer hole 15, and the third pressure transfer hole 16 are sequentially opened, so as to open, seat, and unseal the device in the above-mentioned use process. Adopt the pressure transmission in each biography pressure hole of check valve control, not only make the pressure value of each biography pressure hole transmission more accurate, avoided first sliding sleeve 2, packing element 4 and second sliding sleeve 3 moreover when not needing to pressurize and the liquid in the inside cavity of dabber 1 to take place the contact, and then improved the device's life.
In an alternative embodiment, the mandrel 1 comprises a first sealing groove to improve the tightness of the device. The first sealing groove is positioned on the outer wall of the mandrel 1 contacted with the first sliding sleeve 2, and a sealing ring is arranged in the first sealing groove.
Based on the same concept, the mandrel 1 further comprises a second sealing groove to improve the sealing performance of the device. The second sealing groove is located on the outer wall of the mandrel 1, which is in contact with the second sliding sleeve 3, and is located between the rubber sleeve groove 13 and the second sliding sleeve groove 14, and a sealing ring is arranged in the second sealing groove.
Further, the mandrel 1 further comprises a fourth sealing groove, the fourth sealing groove is located on the outer wall of the mandrel 1, which is in contact with the second sliding sleeve 3, the fourth sealing groove is axially located on one side, away from the first sliding sleeve 2, of the second sliding sleeve groove 14, and a sealing ring is arranged in the fourth sealing groove.
In addition, the second sliding sleeve 3 is provided with a third sealing groove, the third sealing groove is positioned on the inner wall of the separating ring 32, which is contacted with the outer wall of the second end of the mandrel 1, and a sealing ring is arranged in the third sealing groove, so that the sealing performance of the device is further improved.
In summary, in the embodiment of the invention, the rubber sleeve is protected by the first sliding sleeve covering the rubber sleeve in the well entering process of the device, after the device reaches the operation position, the first sliding sleeve is controlled to slide axially by means of pressurization in the oil pipe so as to expose the rubber sleeve, the rubber sleeve is expanded by continuous pressurization, and the packer is successfully set; when the packer is unsealed, the second sliding sleeve is continuously pressurized and controlled to slide axially to enable the rubber sleeve to be fully recovered, and the second sliding sleeve covers the rubber sleeve again to protect the rubber sleeve. The device simple structure, convenient to use, the protection mode of overlay type has not only reduced the wearing and tearing of packing element, has still avoided the fluid erosion to the packing element in the pit shaft, therefore has prolonged the life of packer, has increased the success rate of packer setting, deblocking to make the packer can follow the drilling and go into the well, enlarged the operation scope of packer.
Furthermore, the embodiment of the invention controls the pressure transmission of each pressure transmission hole through the check valve, thereby improving the accuracy of pressure transmission, avoiding unnecessary contact between the device and oil carrying high pressure, and further prolonging the service life of the packer; in addition, this embodiment has still adopted a plurality of sealing washers, has improved the leakproofness of this packer.
All the above optional technical solutions may be combined arbitrarily to form the optional embodiments of the present disclosure, and are not described herein again.
The above description is only exemplary of the present invention and should not be taken as limiting the invention, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.